Black shadows along landscape seems


I am playing around with importing height maps. I am sure I am no doing it right yet but one of the most obvious problems I seem to have is that there are obviously wrong shadows along the seems of my landscapes.
After I hit “build” it builds the lighting and then the black shadows appear near the borders.
I have added ImportanceVolumes for each of my tiles (there was an error at first which is fixed now).
Am I missing something else ?

My first guess is that they are overlapping. What happens when you distance them apart?

sorry for the delay, I didn’t have time lately.
It is not overlapping terrain.

here another two screenshots


all I do is create a new map , import two heightmaps (following the documentation rules regarding landscape sizes i.e. 1009x1009)
then I align them and rebuild lights.

on both landscapes I set the static light resolution from 1.0 to 4.0 (as suggested in some other forum threads)

any suggestion would be appreciated!

It seems to be the lightmap resolution still not high enough, comparing the screenshots in your first and second posts. Instead of using separate 1k landscapes i’d go for a single 2k one though.

Edit: Btw, try a single lightmass importance volume covering both landscape then build the lights again and see if it helps.

I have put an importance volume around the two terrains, didn’t really change much.
I have now put the static resolution from 4.0 to 10.0 not sure how long it will take to build.

the reason why I use smaller terrains is just because its a test right now - eventually I want to setup a streamed terrain made of several chunks of landscapes.

okay so after my unreal crashed when trying to build with 10.0 I tried again with a resolution of 8.0 and the result is the same :-/


Anyone knows how I can fix this? I tried again in the 4.3 preview and I still get these weird artefact shadows along the seems of my terrains

Is it possible for you to upload the map somewhere so that we can take a look at it/try some stuff ? :slight_smile:

I sent you a private message with a simple test project.

Ok, I will take a look at it

As far as I can see you just have to work more carefully :stuck_out_tongue: Those shadows will appear when some of the landscape parts aren’t connected very well:


The red part was overworked by me and as you can see, no wrong shadows are there.

How I did it:

  1. First of all import your landscapes
  2. make sure that the part, where the landscapes are connected, is overlapping a little bit
  3. now decrease (erosion tool), increase or smooth the overlapping seams so that they are connected very well

Oh oh that would be a problem though because my terrains are created in Wold machine.
That would mean I need to go through all my terrains and manually fix them… ouch!

What lighting resolution did you use?

Ps:nvm just saw its 1.0

Actually the standard resolution ^^ (1.0)


Yep, you already saw it :slight_smile:

Have you tried placing those landscapes with World Browser and see how lighting builds like that?

how did you modify both terrains with the smooth tool and guarantee that they share the same vertex height for each vertex along the seam ?

when I try use the smooth tool it only modifies the “current” terrain.

yes Jacky, I used to place them with world browser in 4.2 and with world composition minimap in 4.3

I just increased one landscape at the seam and then I smoothed the part that is overlapping:


Smooth the part where the arrow is pointing at

I’m sorry I tried to do what you said here but like that the terrain vertices don’t match/coincide anymore at all.
If I just smooth one side of the terrain (even if I make them overlap - which sounds like a strange idea) then if I look at the terrain from the opposite side of the seam I see a gap between the two terrains - surely that can’t be right. I am probably not doing exactly what you are doing. Could you describe a bit in more detail what you did ?

I will record you a video -> but of course you will see something like a seam, but you can hide it with meshes :slight_smile:

Here we go:

Thats how I would do it (of course you will have to do it much more precise :p)